42 BOTANY. small extent soluble in water, and the solution has an acid reaction. It yields a hght yellow precipitate with acetate of lead. The part of the alco¬ holic extract that is insoluble in water is easily soluble in alkalies. It also dissolves in nitric acid at a moderate heat, whereby oxydation takes place. On addition of water, a yellow, brittle mass is precipitated." The Mexi¬ cans are said to use an infusion of the leaves for bathing in, in rheumatic affections. See Vol. Ill, Wheeler's Reports, pp. 608.-9. Rhus diveesiloba, T. & G. Poison Oak, Yeara.—Kvich. like our poison oak of the Eastern States. Common on the Pacific coast. For remedy see Grindelia robusta. Negundo aceeoides, McBuch. Box-Elder.—Bearing in mind the great success of the experiments with this tree in Kansas and Nebraska, and its wide range over the more arid areas of our Southwest, it may be well to remember it in further attempts at tree culture. Though hardly to be considered as a valuable timber, it may fairly be reckoned on the shade and fuel list, and fairly associated in this respect with the following: ScHiNUS MOLLE, Linn., from Mexico and South America.—Now grown in Southern California under the name of Pepper Tree and Chili Pepper. Peosopis julifloea, DC. Mesquit. Algaroba of the Mexicans.—Grows from Southeastern California east to Texas, where it attains the tree size, and forms dense thickets; extends south into South America. The gum exud¬ ing from this tree closely resembles gum arable in appearance and in its properties, and may some day become an important article in trade. The pods while yet in pulpy condition are a valuable forage, eagerly eaten by animals, and on which they actually thrive while making hard marches. The beans contain thirty per cent, of grape-sugar. Dr. Loew asserts that the Comanche Indians prepare an alcoholic beverage from them. As a fuel it ranks with the hickory of the Eastern States, and the charcoal made from it is said by Dr. Loew to be of the best quality for metallurgical and smelting purposes. Besides this species, there is another, hardly less useful, i. e., P. pubescens, Benth., the Sceew-Bean, the pods of which are ground into flour by the Indians. The wood of both species is of great value in some of the arts.